This is a rare natural hybrid from California (Ferocactus peninsulae x Ferocactus rectispinus) and is very hard to find a good size plant  in cultivation.

Description:  Small barrel cactus, usually solitary..
Stem: Spherical, green to pale bluish with a yellowish woolly depressed apex, 21 cm tall and 30 cm in diameter, as it ages it will become cylindrical an can reach 1m in height and 35 cm in diameter
Ribs: 15 to 21, sharp and with deep furrows about 3 cm highly
Areoles: The areoles are upward elonged with a short white felt covers; they stand on protruding bump on the ribs.
Spines: About 8, of which one central upright and very strong, basally enlarged, abaxilly flatted +/- hooked. The colour is purplish at the base and reddish yellow on the tips. Other 5 spines less strong of same colour and slightly curved at the point, are regularly arranged with the smallest of which at the base of the areole; there are also two very thin whitish lateral spine and an upper rudimentary aciculate spine thinner and shorter.
Flowers: 5 cm long 6 cm in diameter, yellow-orange to brick–red with darker midline, they come from the wooly apex of the plants.
Blooming season: Between at the end of July and beginning of September.

Ferocactus × californicus (Cels ex Labouret) Borg

Natural hybrid (Ferocactus peninsulae x Ferocactus rectispinus)

Scientific name: Ferocactus californicus (Monville) Borg,
Published in: Cacti, 235, 1937

Basionym: Echinocactus californicus Monville 1846
 

Origin: California

Conservation status: Listed in CITES appendix 2.

• Echinocactus viridiscens,

Flowers are very showy 5 cm long 6 cm in diameter, yellow-orange to brick-red with darker midline.

Cultivation: Prefers full sun,  Avoid frost.  

Propagation: Seeds are the only way of reproducing.